FILE PHOTO: A sign stands outside a Bristol Myers Squibb facility in Cambridge, Massachusetts, U.S., May 20, 2021. REUTERS/Brian Snyder/File Photo

By Christy Santhosh

(Reuters) -Drugmaker Bristol Myers Squibb said on Friday it will acquire privately held cell therapy developer Orbital Therapeutics for $1.5 billion in cash, aiming to diversify from legacy products facing competition from generic drugs.

The deal expands Bristol Myers Squibb's CAR T-cell immunotherapy portfolio with Orbital's lead experimental candidate, OTX-201, which is designed to target autoimmune diseases.

This marks the company's first major acquisition of the year, as it shifts focus beyond established blockbusters, such as the blood thinner Eliquis and cancer drug Revlimid, to reassure investors that its newer therapies can drive future growth.

BMO Capital Markets analyst Evan Seigerman, however, said the acquisition is "a strategic fit, but not the deal to help change Bristol's narrative".

Bristol Myers shares fell about 1% in early trade.

Seigerman added that the therapeutic burden and logistical challenges of administering these autoimmune cell therapies will likely limit their use to the most severe patient populations.

Traditional CAR T-cell therapies involve taking immune cells from a patient, modifying them in a lab and reinfusing them into the patient - a process that is complex and expensive.

Massachusetts-based Orbital's OTX-201, however, works in vivo, meaning the patient's own body becomes the site of CAR-T cell generation, bypassing the need for external cell engineering.

Bristol will also gain access to Orbital's RNA technology, which combines various RNA engineering, advanced delivery methods and artificial intelligence to create customizable treatments for a wide range of diseases.

In March, the company had made a smaller acquisition of its partner 2seventy bio for about $286 million in cash, saving future profit-sharing costs on Abecma, a CAR T-cell therapy for a type of blood cancer called multiple myeloma.

Abecma and blood cancer cell therapy Breyanzi accounted for about 1.7% of Bristol Myers' total revenue last year.

(Reporting by Christy Santhosh in Bengaluru; Editing by Vijay Kishore)